Giant Pokémon is the term given to Pokémon specimens which have developed to many times their normal size, usually by artificial means. These Pokémon were thought to have first appeared during the
Pokémopolis dynasty, when Pokémopolitan scientists exercised their newfound knowledge to create these kinds of Pokémon to terrify their opposition into submission.
Our researchers have reason to believe that such a reaction is an adverse response to a sudden introduction of concentrated amounts of
Expanon, the same substance which a Pokémon is made from. This belief has been backed up following the appearances of a giant
Treecko in Sedoku City,
Hoenn, and secondly, the sighting of a giant
Caterpie in Lavender Town,
Kanto. All three of these Pokémon were known to have been exposed to large amounts of excess Expanon prior to their growth. Such a high concentration would force a Pokémon's cells to develop too quickly, leaving its natural evolution responses no time to take place. Instead, the Pokémon's body mass would increase rapidly.
In the case of the present day accidental enlargements, the reaction proved to be temporary, though in the case of the Caterpie, evolution was sped up during its period of enlargement. An exceptional circumstance was the creation of 'Beta Groudon' in Forina, Hoenn.
Another exceptional circumstance was the existence of a giant
Claydol on Izabe Island, Hoenn. It is not known whether this Pokémon was created during or after the Pokémopolis dynasty, but it is thought that a combination of
Cho'moken-induced evolution and the artificial origins of the Pokémon itself were responsible for keeping it at a large size.
Tentacruel that enlarged following exposure to an unknown chemical concoction was able to use some form of telepathy by manipulating another Pokémon which was able to speak the human language. The Tentacruel still lives somewhere in the depths of the ocean off south Kanto.
Giant Pokémon shouldn't be confused with Pokémon that have reached their maximum size for their evolutionary level. For example, a newly evolved
Roselia is normally a foot tall but at its peak of growth it can be as high as 3 ft, taller than a newly evolved